Black-crowned Night Heron

Black-crowned Night Heron (Nycticorax nycticorax) is a stocky medium-sized heron whose adults have a black crown and back, pale grey wings, red eyes and short yellow legs. Body shape, bill structure, plumage pattern and voice provide the strongest field characters. Age, sex and season may alter its appearance, so identification should combine several features and careful direct field comparisons with similar species in the same habitat (Wikipedia, general species account).

It rests communally by day and feeds mainly from dusk onward around wetlands, taking fish, amphibians, crustaceans and other small animals from shallow water. Its movements and social behaviour vary through the year, with breeding birds generally more dispersed and non-breeding birds gathering where food is concentrated. Japanese records place it within the country's documented avifauna as a resident, migrant or visitor (Wikipedia, general species account; Wildlife of Japan occurrence records).